GRAS 40HL 1/2'' LEMO 低噪声传声器系统

Freq range: 10 Hz to 16 kHz
Dyn range: 6.5 dB(A) to 110 dB
Sensitivity: 850 mV/Pa

GRAS 40HL 1/2" 低噪声传声器系统可测量接近人类听力阈值的声压级。因此，它通常适用于非常安静的产品的声功率测量。它的动态范围非常宽，可测量 20 μPa 时低至 6.5 dB（1/3 倍频程频带）的 20 Hz 至 20 kHz 的声压级。

Technology

Typical applications and use

Measurements at very low sound pressurelevels
Measurements on hard-disk drives, computerproducts, anechoic rooms, quiet rooms, etc
Sound-power measurements at low levels

Design

The 40HL comprises a special high-sensitive 1/2" free-field measurement microphone and an integrated 1/2" low-noise preamplifier. In combination, they connect to most high-quality input modules with LEMO 1B connector.

It complies with IEC 61672 class 1.

Preamplifier

The preamplifier, a true 1/2" low-noise amplifIer with LEMO 1B connector, has a built-in compensation filter for free-field microphones.

Microphone

The 1/2" microphone is an externally-polarized free field microphone with a specially reduced inherent noise floor in order to achieve a high dynamic range and wide frequency range. Its diaphragm is specially tuned to yield high sensitivity coupled with low internal noise.

TEDS

The preamplifier of the 40HL has TEDS according to IEEE 1451.4. If your measurement platform supports TEDS you can read and write data like properties and calibration data.

Operating 40HL

For holding the microphone, you can order tripods and for level calibration of you need a pistonphone and Calibration Adapter attenuating the pistonphone signal to 94 dB re. 20 µPa. See the tab Ordering info.

Specifications

Frequency range (±1 dB)

12.5 to 10k

Frequency range (±2 dB)

10 to 16 k

Frequency range (±3 dB)

6 to 20k

Dynamic range lower limit (microphone thermal noise)

dB(A)

6.5

Dynamic range upper limit

110

Set sensitivity @ 250 Hz (±2 dB)

mV/Pa

850

Polarization voltage

200 V / Traditional

Microphone venting

Rear

Output impedance

Temperature range, operation

°C / °F

–20 to 60 / -4 to 140

Temperature range, storage

°C / °F

-40 to 85 / -40 to 185

Temperature coefficient @250 Hz

dB/°C / dB/°F

-0,007 / -0,004

Static pressure coefficient @250 Hz

dB/kPa

-0.01

Humidity range non condensing

% RH

0 to 95

Humidity coefficient @250 Hz

dB/% RH

0,001

Influence of axial vibration @1 m/s²

dB re 20 µPa

TEDS (IEEE 1451.4)

27 v. 1.0

Connector type

7-pin LEMO (FGG.1B.307)

CE/RoHS compliant/WEEE registered

Yes / Yes / Yes

Typical frequency response

Typical noise floor shown in 1/3-octave bands - linear and A-weighted

GRAS Sound & Vibration reserves the right to change specifications and accessories without notice.

Ordering info

Optional items

GRAS AA0008	3 m LEMO-to-LEMO cable*
GRAS AA0009	10 m LEMO-to-LEMO cable*
GRAS 12AD	1-Channel Power Module
GRAS 12AR	2-Channel Power Module
GRAS 12AA	2-Channel LEMO Power Module with gain, filters and Syscheck generator
GRAS 12AK	1-Channel Power Module with gain, filters and SysCheck generator
GRAS 12AQ	2-Channel Universal Power Module with signal conditioning and PC interface
GRAS AL0006	Tripod
GRAS RA0093	Adjustable, high quality, stainless steel tripod adapter
GRAS AM0069	Windscreen for 1/2" Microphones
GRAS 42AP	Intelligent Pistonphone, Class 0
GRAS 42AA	Pistonphone, Class 1
GRAS RA0090	94 dB Pistonphone Coupler

*The cables also function as connection cables (to connect 40HL to a power module).